1. If you just want to check the version information of the Oracle database, simply connect and login to the Oracle database with SQL *Plus. Upon login, you will see:
SQL*Plus: Release 126.96.36.199.0 – Production on Tue Oct 18 17:58:57 2005
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Oracle9i Enterprise Edition Release 188.8.131.52.0 – 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 184.108.40.206.0 – Production
The first italic number is the version of the SQL*Plus client and the second italic number is the version of Oracle database which you are connected to .
2. Retrieve the version information from v$version table by using SQL*Plus. In this table you can find version information on Oracle, PL/SQL, etc.
To retrieve the version information for Oracle, you execute the following SQL statement:
select * from v$version where banner like 'Oracle%';
It should return something like this:
Oracle9i Enterprise Edition Release 220.127.116.11.0 – 64bit Production
3. Version information can also be checked from Installed Products from the Oracle Universal Installer. It will tells you what products is installed on the machine and also its version information too.
In Unix, the installer is located at $ORACLE_HOME/bin/runInstaller.
In Windows, access the installer by Start -> All Programs -> Oracle Installed Products -> Universal Installer.